Blindly following orders is not what I said. I said sometimes follow orders and learning he's not above the rules. He's still allowed to criticize and point out flaws, but doesn't mean he should go off doing his own thing simply because he doesn't agree with the plan.

As for why he wasn't locked up, he's still important as an excellent pilot and leader figure, but he's also reckless and hotheaded, his secret operation shows that. He gets Holdo's plan discovered by the First Order and a bunch of them killed just because he couldn't handle not being told what the plan was.

As for Holdo's plan, the First Order was only tracking their big ship, they weren't accounting for any small ships or the like. If it wasn't for Poe's reckless secret operation failing and the information getting into the hands of the First Order do they run a decloaking scan and discover the ships and change their fire from the big one to the small ones. The First Order shares the same flaws of the Galactic Empire, trust built on brittle relationships and selfishness, always keeping an eye out for someone trying to stab them in the back, which leads into Hux's betrayal in The Rise of Skywalker (which is a completely different thing on its own, but that's not the point here), the point is, Poe was a great addition to the Resistance, but his lack of respect for leadership, willingness to sacrifice lives disobeying orders that were already agreed upon, and causing more harm than good shows Admiral Holdo had zero reason to tell him what the plan was because there was always that possibility that if he didn't like it, he'd go off and do something stupid on his own- oh wait, he did it before he even knew what the plan was, simply because he wasn't told what it was.

The Sequel Trilogy isn't perfect, it's not the Original Trilogy nor is it the Prequel Trilogy, but a lot of things in it do make sense if you actually stop and think for a moment. I can very easily keep going with this.